Hello! In the function start_process_measurement() in the file src/process/do_process.cpp events are added to perf_bundle: perf_events->add_event("irq:softirq_entry"); perf_events->add_event("irq:softirq_exit"); perf_events->add_event("timer:timer_expire_entry"); perf_events->add_event("timer:timer_expire_exit"); perf_events->add_event("hrtimer_expire_entry"); /* !!! */ perf_events->add_event("hrtimer_expire_exit"); /* !!! */ if (!perf_events->add_event("power:cpu_idle")){ perf_events->add_event("power:power_start"); perf_events->add_event("power:power_end"); } As you may see all events are prefixed with the subsystem name. All but hrtimer_expire_entry and hrtimer_expire_exit. And without "timer:" prefix these events are never catched. So I have added this prefix and see that events are intercepted as needed. But event parser complains about wrong event format: unknown op '{' failed to read event print fmt for hrtimer_expire_entry It seems that event parser can't handle square bracket in print format for the event: print fmt: "hrtimer=%p function=%pf now=%llu", REC->hrtimer, REC->function, (unsigned long long)(((ktime_t) { .tv64 = REC->now }).tv64) So is the absence of "timer:" prefix a bug or a commenting of non-working case? Thank you. -- Best regards, Igor Zhbanov, Expert Software Engineer, phone: +7 (495) 797 25 00 ext 3806 e-mail: i.zhbanov(a)samsung.com ASWG, Moscow R&D center, Samsung Electronics 12 Dvintsev street, building 1 127018, Moscow, Russian Federation